The subject matter disclosed herein relates to an ultrasonic imaging apparatus and an image processing apparatus which extract a surface image of a massive tissue in a subject from 3D tomographic image data on the subject and display it stereoscopically.
Recently, in the field of diagnostic imaging using an ultrasonic imaging apparatus, volume rendering in which a surface image of a massive tissue such as a fetus is extracted according to 3D tomographic image data and displayed stereoscopically has been performed. This stereoscopic display makes it easy for an operator to get an overall picture of the massive tissue (for example, see Japanese Patent Application No. 2003-204963).
In this surface image extraction, positional information on a massive tissue region to be extracted is specified using a 2D region of interest as set in a corresponding 2D tomographic image. As for the 2D region of interest including the massive tissue region, the operator forms a borderline constituting the boundary of the 2D region of interest, using a cursor on the 2D tomographic image. A 3D region of interest is formed by automatically expanding the borderline in a direction orthogonal to the 2D tomographic image.
However, according to the above background art, the position of the stereoscopically displayed surface image of the massive tissue is not well balanced in the 3D region of interest. In other words, the boundary constituting the surface of the massive tissue falls within the 2D region of interest but may not fall within the automatically expanded 3D region of interest. If that is the case, a stereoscopic display of the surface image is not a stereoscopic display spreading all over the 3D region of interest but a stereoscopic display only in a limited part of the region.
Since the purpose of a stereoscopic display of a surface image is to enable one to grasp an overall picture of a massive tissue easily, a stereoscopic display only in a limited region is not desirable. Therefore, the operator has to set a 2D region of interest repeatedly so that the boundary constituting the surface of the massive tissue spreads all over the 3D region of interest, which means that it takes much time and labor to obtain a final stereoscopic display.
On the other hand, in a clinical scene, a subject will feel much relieved if an image of her fetus is stereoscopically shown to her. In this case, if it should take time and labor to make a stereoscopic display of the fetus after capturing 3D tomographic image data, it would be frustrating and undesirable for both the operator and the subject.
For the above reasons, it is imperative to realize an ultrasonic imaging apparatus and an image processing apparatus that easily and quickly set a 2D region of interest to maximize the spread of a boundary constituting the surface of a massive tissue over a 3D region of interest.